/*
 *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

package im.zego.CustomerVideoCapture.ve_gl;

import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.SurfaceTexture;
import android.view.Surface;
import android.view.SurfaceHolder;

import javax.microedition.khronos.egl.EGL10;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.egl.EGLContext;
import javax.microedition.khronos.egl.EGLDisplay;
import javax.microedition.khronos.egl.EGLSurface;

/**
 * Holds EGL state and utility methods for handling an egl 1.0 EGLContext, an EGLDisplay,
 * and an EGLSurface.
 */
public final class EglBase10 extends EglBase {
    // This constant is taken from EGL14.EGL_CONTEXT_CLIENT_VERSION.
    private static final int EGL_CONTEXT_CLIENT_VERSION = 0x3098;

    private final EGL10 egl;
    private EGLContext eglContext;
    private EGLConfig eglConfig;
    private EGLDisplay eglDisplay;
    private EGLSurface eglSurface = EGL10.EGL_NO_SURFACE;

    // EGL wrapper for an actual EGLContext.
    public static class Context extends EglBase.Context {
        private final EGLContext eglContext;

        public Context(EGLContext eglContext) {
            this.eglContext = eglContext;
        }
    }

    // Create a new context with the specified config type, sharing data with sharedContext.
    public EglBase10(Context sharedContext, int[] configAttributes) {
        this.egl = (EGL10) EGLContext.getEGL();
        eglDisplay = getEglDisplay();
        eglConfig = getEglConfig(eglDisplay, configAttributes);
        eglContext = createEglContext(sharedContext, eglDisplay, eglConfig);
    }

    @Override
    public void createSurface(Surface surface) {
        /**
         * We have to wrap Surface in a SurfaceHolder because for some reason eglCreateWindowSurface
         * couldn't actually take a Surface object until API 17. Older versions fortunately just call
         * SurfaceHolder.getSurface(), so we'll do that. No other methods are relevant.
         */
        class FakeSurfaceHolder implements SurfaceHolder {
            private final Surface surface;

            FakeSurfaceHolder(Surface surface) {
                this.surface = surface;
            }

            @Override
            public void addCallback(Callback callback) {}

            @Override
            public void removeCallback(Callback callback) {}

            @Override
            public boolean isCreating() {
                return false;
            }

            @Deprecated
            @Override
            public void setType(int i) {}

            @Override
            public void setFixedSize(int i, int i2) {}

            @Override
            public void setSizeFromLayout() {}

            @Override
            public void setFormat(int i) {}

            @Override
            public void setKeepScreenOn(boolean b) {}

            @Override
            public Canvas lockCanvas() {
                return null;
            }

            @Override
            public Canvas lockCanvas(Rect rect) {
                return null;
            }

            @Override
            public void unlockCanvasAndPost(Canvas canvas) {}

            @Override
            public Rect getSurfaceFrame() {
                return null;
            }

            @Override
            public Surface getSurface() {
                return surface;
            }
        }

        createSurfaceInternal(new FakeSurfaceHolder(surface));
    }

    // Create EGLSurface from the Android SurfaceTexture.
    @Override
    public void createSurface(SurfaceTexture surfaceTexture) {
        createSurfaceInternal(surfaceTexture);
    }

    // Create EGLSurface from either a SurfaceHolder or a SurfaceTexture.
    private void createSurfaceInternal(Object nativeWindow) {
        if (!(nativeWindow instanceof SurfaceHolder) && !(nativeWindow instanceof SurfaceTexture)) {
            throw new IllegalStateException("Input must be either a SurfaceHolder or SurfaceTexture");
        }
        checkIsNotReleased();
        if (eglSurface != EGL10.EGL_NO_SURFACE) {
            throw new RuntimeException("Already has an EGLSurface");
        }
        int[] surfaceAttribs = {EGL10.EGL_NONE};
        eglSurface = egl.eglCreateWindowSurface(eglDisplay, eglConfig, nativeWindow, surfaceAttribs);
        int error = egl.eglGetError();
        if (eglSurface == EGL10.EGL_NO_SURFACE || error != EGL10.EGL_SUCCESS) {
            throw new RuntimeException(
                    "Failed to create window surface: 0x" + Integer.toHexString(error));
        }
    }

    // Create dummy 1x1 pixel buffer surface so the context can be made current.
    @Override
    public void createDummyPbufferSurface() {
        createPbufferSurface(1, 1);
    }

    @Override
    public void createPbufferSurface(int width, int height) {
        checkIsNotReleased();
        if (eglSurface != EGL10.EGL_NO_SURFACE) {
            throw new RuntimeException("Already has an EGLSurface");
        }
        int[] surfaceAttribs = {EGL10.EGL_WIDTH, width, EGL10.EGL_HEIGHT, height, EGL10.EGL_NONE};
        eglSurface = egl.eglCreatePbufferSurface(eglDisplay, eglConfig, surfaceAttribs);
        int error = egl.eglGetError();
        if (eglSurface == EGL10.EGL_NO_SURFACE || error != EGL10.EGL_SUCCESS) {
            throw new RuntimeException("Failed to create pixel buffer surface with size " + width + "x"
                    + height + ": 0x" + Integer.toHexString(error));
        }
    }

    @Override
    public EglBase.Context getEglBaseContext() {
        return new Context(eglContext);
    }

    @Override
    public boolean hasSurface() {
        return eglSurface != EGL10.EGL_NO_SURFACE;
    }

    @Override
    public int surfaceWidth() {
        final int widthArray[] = new int[1];
        egl.eglQuerySurface(eglDisplay, eglSurface, EGL10.EGL_WIDTH, widthArray);
        return widthArray[0];
    }

    @Override
    public int surfaceHeight() {
        final int heightArray[] = new int[1];
        egl.eglQuerySurface(eglDisplay, eglSurface, EGL10.EGL_HEIGHT, heightArray);
        return heightArray[0];
    }

    @Override
    public void releaseSurface() {
        if (eglSurface != EGL10.EGL_NO_SURFACE) {
            egl.eglDestroySurface(eglDisplay, eglSurface);
            eglSurface = EGL10.EGL_NO_SURFACE;
        }
    }

    private void checkIsNotReleased() {
        if (eglDisplay == EGL10.EGL_NO_DISPLAY || eglContext == EGL10.EGL_NO_CONTEXT
                || eglConfig == null) {
            throw new RuntimeException("This object has been released");
        }
    }

    @Override
    public void release() {
        checkIsNotReleased();
        releaseSurface();
        detachCurrent();
        egl.eglDestroyContext(eglDisplay, eglContext);
        egl.eglTerminate(eglDisplay);
        eglContext = EGL10.EGL_NO_CONTEXT;
        eglDisplay = EGL10.EGL_NO_DISPLAY;
        eglConfig = null;
    }

    @Override
    public void makeCurrent() {
        checkIsNotReleased();
        if (eglSurface == EGL10.EGL_NO_SURFACE) {
            throw new RuntimeException("No EGLSurface - can't make current");
        }
        synchronized (EglBase.lock) {
            EGLContext oldContext = egl.eglGetCurrentContext();
            EGLSurface oldSurface = egl.eglGetCurrentSurface(EGL10.EGL_DRAW);
            if (oldContext == eglContext && oldSurface == eglSurface) {
                return ;
            }

            if (!egl.eglMakeCurrent(eglDisplay, eglSurface, eglSurface, eglContext)) {
                throw new RuntimeException(
                        "eglMakeCurrent failed: 0x" + Integer.toHexString(egl.eglGetError()));
            }
        }
    }

    // Detach the current EGL context, so that it can be made current on another thread.
    @Override
    public void detachCurrent() {
        synchronized (EglBase.lock) {
            if (!egl.eglMakeCurrent(
                    eglDisplay, EGL10.EGL_NO_SURFACE, EGL10.EGL_NO_SURFACE, EGL10.EGL_NO_CONTEXT)) {
                throw new RuntimeException(
                        "eglDetachCurrent failed: 0x" + Integer.toHexString(egl.eglGetError()));
            }
        }
    }

    @Override
    public void swapBuffers() {
        checkIsNotReleased();
        if (eglSurface == EGL10.EGL_NO_SURFACE) {
            throw new RuntimeException("No EGLSurface - can't swap buffers");
        }
        synchronized (EglBase.lock) {
            egl.eglSwapBuffers(eglDisplay, eglSurface);
        }
    }

    // Return an EGLDisplay, or die trying.
    private EGLDisplay getEglDisplay() {
        EGLDisplay eglDisplay = egl.eglGetDisplay(EGL10.EGL_DEFAULT_DISPLAY);
        if (eglDisplay == EGL10.EGL_NO_DISPLAY) {
            throw new RuntimeException(
                    "Unable to get EGL10 display: 0x" + Integer.toHexString(egl.eglGetError()));
        }
        int[] version = new int[2];
        if (!egl.eglInitialize(eglDisplay, version)) {
            throw new RuntimeException(
                    "Unable to initialize EGL10: 0x" + Integer.toHexString(egl.eglGetError()));
        }
        return eglDisplay;
    }

    // Return an EGLConfig, or die trying.
    private EGLConfig getEglConfig(EGLDisplay eglDisplay, int[] configAttributes) {
        EGLConfig[] configs = new EGLConfig[1];
        int[] numConfigs = new int[1];
        if (!egl.eglChooseConfig(eglDisplay, configAttributes, configs, configs.length, numConfigs)) {
            throw new RuntimeException(
                    "eglChooseConfig failed: 0x" + Integer.toHexString(egl.eglGetError()));
        }
        if (numConfigs[0] <= 0) {
            throw new RuntimeException("Unable to find any matching EGL config");
        }
        final EGLConfig eglConfig = configs[0];
        if (eglConfig == null) {
            throw new RuntimeException("eglChooseConfig returned null");
        }
        return eglConfig;
    }

    // Return an EGLConfig, or die trying.
    private EGLContext createEglContext(
            Context sharedContext, EGLDisplay eglDisplay, EGLConfig eglConfig) {
        if (sharedContext != null && sharedContext.eglContext == EGL10.EGL_NO_CONTEXT) {
            throw new RuntimeException("Invalid sharedContext");
        }
        int[] contextAttributes = {EGL_CONTEXT_CLIENT_VERSION, 2, EGL10.EGL_NONE};
        EGLContext rootContext =
                sharedContext == null ? EGL10.EGL_NO_CONTEXT : sharedContext.eglContext;
        final EGLContext eglContext;
        synchronized (EglBase.lock) {
            eglContext = egl.eglCreateContext(eglDisplay, eglConfig, rootContext, contextAttributes);
        }
        if (eglContext == EGL10.EGL_NO_CONTEXT) {
            throw new RuntimeException(
                    "Failed to create EGL context: 0x" + Integer.toHexString(egl.eglGetError()));
        }
        return eglContext;
    }
}
